does cause foul smell.
Which nasal spray
you are using you have not mentioned .
Upto my knowledge there can be 3 kind of sprays
---- if this is the spray do not use it so frequently and consult your ENT specialist
2.Steroid spray----Do consult a doctor and stop using it as it might be causing Atrophic changes in nose
3. If it is a normal saline spray then it should not cause foul smell-----then that means that you have a infection or you are not using the spray properly.
Do consult your ENT specialist he will examine you and get done a nasal Endoscopy
done to rule out the disease.
You must also see that your dental hygiene is maintained properly and you do not have acid reflux
Get well soon.